منابع مشابه
Deformation of F-purity and F-regularity
For a Noetherian local domain (R, m, K), it is an open question whether strong F–regularity deforms. We provide an affirmative answer to this question when the canonical module satisfies certain additional assumptions. The techniques used here involve passing to a Gorenstein ring, using an anti– canonical cover.
متن کاملFailure of F-purity and F-regularity in Certain Rings of Invariants
Let Fq be a finite field of characteristic p, K a field containing it, and R = K[X1, . . . , Xn] a polynomial ring in n variables. The general linear group GLn(Fq) has natural action on R by degree preserving ring automorphisms. L. E. Dickson showed that the subring of elements which are fixed by this group action is a polynomial ring, [Di], though for an arbitrary subgroupG of GLn(Fq), the str...
متن کاملF-regularity relative to modules
In this paper we will generalize some of known results on the tight closure of an ideal to the tight closure of an ideal relative to a module .
متن کاملF -pure Homomorphisms, Strong F -regularity, and F -injectivity
We discuss Matijevic–Roberts type theorem on strong F -regularity, F -purity, and Cohen–Macaulay F -injective (CMFI for short) property. Related to this problem, we also discuss the base change problem and the openness of loci of these properties. In particular, we define the notion of F -purity of homomorphisms using Radu–André homomorphisms, and prove basic properties of it. We also discuss a...
متن کاملF-regularity Does Not Deform
We show that the property of F-regularity does not deform, and thereby settle a longstanding open question in the theory of tight closure. Specifically, we construct a three dimensional N-graded domain R which is not F-regular (or even F-pure), but has a quotient R=tR which is F-regular. Examples are constructed over fields of characteristic p > 0, as well as over fields of characteristic zero.
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ژورنال
عنوان ژورنال: Journal of Pure and Applied Algebra
سال: 1999
ISSN: 0022-4049
DOI: 10.1016/s0022-4049(98)00014-0